A nano-stabilization technique for low repetition rate phase-sensitive optical experiments

Abstract

A nano-stabilization technique is developed for the observation of Ramsey fringes in low repetition rate Rydberg electron wavepacket experiments. The stabilization system consists of a CCD array monitoring optical interference fringes of a reference CW laser beam passing through a Michelson interferometer, a PID feedback circuit generating an error voltage, and a piezo responding to the error voltage to compensate for geometric fluctuations in the interferometer of nm with a response time ms. The proficiency of the stabilized interferometer is demonstrated in an experiment to observe Ramsey fringes in autoionizing Rydberg states of Xe.

Rydberg wave packets in molecules

“…Briefly, the interferometer is actively stabilised with reference to the interference pattern generated by a continuous wave HeNe laser as it travels parallel to the excitation pulse, through the interferometer. 63 These interference fringes act as a reference for a feedback circuit, which generates an error signal. This error signal aims to retain the reference position and is sent to a piezo (piezoelectric stepper motor) on which the mirror of the moveable arm is mounted.…”

Manipulating electron wave packets

“…Experimentally, this scheme requires precise control of the phase diOE erence between the two optical pulses, which in turn requires a stabilized interferometer. This may be accomplished by locking a feedback circuit on to a fringe pattern generated in the same interferometer, an example of which has been discussed in detail by Hong et al (1998).…”